Reindex taking long time.

Hi Guys,
I have a table with more than3 Billion records nad tried to rebuild the indexes. the rebuild has ran around 16 hours but still not finished (hence i killed the session). Can anybody suggest better approach to do this activity. I will get max 8 hour down time.

No, I donot want all, however those have frag > 10% I should do. As mentioned the big tables needs to do the reindexing periodically (i mean atleast once in a month) to perform better. But this is taking long time and i could not predict when it finish . I do not find any method to find out the time to finish.

Not much, since the issue is "taking time". I need to go for some technique to reduce the indexing time. I have procedure to find out the fragmented tables and initiate the indexing task. If try powershell script or some index filter method will I can achive something?

I tried to reorganise the index initially, but it took long time (around 40 Hours), so i drop that method. Now i am tring to do the reindex offline by taking the table back up and reindex it and restore it. What you say?

If it is partitioned why you are performing REORG or REINDEX for old partitions?
Just make the old ones are READ only to reduce the time.

just check whether you partitioned the data in the right way so that you can keep the old data in different partitions from current data (I mean the inserts/updates/deletes should happen in current partition)